Anchorage insert for screwthreaded fastenings



A Maly 14, 1946. w. E. 'GREENE 2,400,343

ANCHORAGE INSERT FOR SCREW-THREAD@ FASTENINGS 'Filed My 15, 1943 2 sheets-sheet 2 46." JNVENTOR eene,

F e 5 mw.. r/O 1 7 m., Vw U Tra-..15

May 14, 1946. 4

l ANCHORAGE IIN-SERT FORrSCREW-THREADED FASTENINGS Filed May l5, 1945 2 Sheets-Sheet 1 39 I :ICT- Es 3.9 f

-INVEN-TOR.

v v v .BY I l v rma-E l A rov'y Patented May v14, 1946 ANcHonAGE-INSERT Fon sonliw-Y l' I' v THREADED FAsTENJNos.

Whitney E .Grena' Hollywood, Calif. Application May 15, 1943, Serial No. 487,156

` rs claims.l cl'.s5'32 The invention has for ank object to` provide insert vdevices suitable for mounting bolts or nuts upon relatively soft materials, tothe endthat parts may be secured together, brackets'secured in place, or elements removably Securedv upon bodies of relatively soft materials, especially wood,A although the invention is also applicable to the use of inserts in metals of various rkinds, as might be desirable in the .case of soft metals such as aluminum, lead,V and. the like..

My invention derives especial importance at present. from the past developments ,ofplywood construction, particularly as usedA in aircraft,- and my invention enables attachment of parts. together or the, application'of screw-threaded iastenings for the 'attachmentof members or parts to plywood constructions witha minimum liability of loosening of thev fasteningsyand with the attainment vof greater security, greater facility-of use. of fastenings required to be :removed from time to time, .and increasing the field-oi use of fastenings or removable parts upon-or; in' plywood construction with'enhancedl security.- -lIt is. also an aim of myv invention-toename theattachment of plywood partsy together and the mounting of members upon plywood construytions without. the liability of enlargement of openings or the deformation of keyor vslot parts in openings which receive fastening members, and also to eliminate the abrasion. and Wear of the woodsurfaces which vis ordinarily involved by the insertion of bolts through plywood structures, and the application -of nuts over Washers thereon. .1

I-t is an especially important ,aim or my invention to present a means for mounting female or stud inserts in wood by the-v use of lsore-w threads engaging the wood structure to hold the insert elements against w-ithdrawal,and with the requirement of a minimum depth of insertionof the insert, while yet sustainingvample strength and security in the mounting elements thereon.

Another important aimof the invention is to present a novel construction of locking .device and shear-stress-sustaining mem-ber sueltas a stud or other insert, to the end that shear stresses upon studs or the like set in woodjmay heV .safely sustained without liabilityv of loosening of the members mounted in the wood, `and without liability of yworking loose ofthe insert in the wood structure. It is an important purpose alsoto combine a locking means and shear-'streSS-SUS- taining function in a single. element and simple form. A v'further aimY in this connection is to Figure 7.

vstress sustaining meansl,A and that is toprovide not only. an anchor means-to lock the insert member against rotation more keying of the insert to the locking means as wel-l .as distributing shear stresses vover :a wide area in a support structure, but, in addition, to provide toran automatic adaptation of the, locking means. to the size of the insert, produced by a functioning of the article resultant-upon its application tothe work. Anotherobjeot of., the invention isY to present a ndvelmethodot vkeying aninsertto Athe body structure uponwhich itis applied.

I am aware that a locking means has been provided for screw-.threaded inserts, consisting o f a ring interiorlyand exteriorly serrated, the insertbeing'also serrated yjust within the ring, but these ,serrated rings occasionally drop out before final assembly, and the inherent requirements offmanufaotureand manner .of use of such article prevent itil-om Vfunctioning `properly for sustaining shear stresses, transmitted to the insert, an d ity isy an object of; my invention to overcome this .Clifiilimty,A Y

Additionalobgiectg advantages and features of invention resido inthe .oonstructiomarrangement. and: combination of partsinvolved in the embodiment of my invention, as will be more readily understood from the following description and accompanying drawings, wherein Figure 1 isa fragmentary sectional view of a body structure such as might be made of wood, in which thereiis set a stud bolt by the use of my invention.;A a removable body piece being shown as secured to the structural member by means of a st-ud bolt and a nut engaged thereupon.

Figure ,2'V is atop view of Figure 1, with the secured memberv mit removed, being in section on the line 2.-.-1'of Figure l, the plane of the section; of Figure 41 being indicated by the line .,-.I in Fig-ure 2. 1 l

Figure '3 is a sectional view at right angles to Figure, on the line 3-3 of Figure 1';

Fig-'ure 41 is a detail rtop view of the locking members for the stud applied to the base structure in which vthe stud is set.

Figure 5 i-s an edge view of the locking member of Fig-ure 4. Figure 'isja sectional view similar to Figure l, showing a modification, taken on the line 6 6 of `Figure 7 is a top view with the vstud in section on the line; 1-7 ofFgure. 6.

Figure 8 i- S ootion through the lgey element embody four functions in the klocking and shear 55 of the stud, dellacned,v as shown in 'Figures 6 and?.

devices and stud element engaged, taken at right angles to Figure 10, on the line "ll-Y-VH of Figure 12;

Figure 12 is a top view of the structure of Fig.-

ure 11, with the stud member in section, on: the y line IZ-IZ of Figure 11.

Figure 13 is a detail of the female insert memi ber detached.

Figure 14 is a top view of the insert memberalone. s

the bore 28 until the extremity of the stud is near the bottom of the bore, and the unthreaded ".cylindrical portion 32 of the stud extends to the Figure 15 is a view similar to Figure 10, showing a modification of the female insert.

Figure 16 is a view similar to Figure 11, showing the fastening for the insert engaged and a stud set in the insert, this view being taken onthe line 1Ii---li of Figure 17.

Figure 1'7 is a horizontal sectional view line Il-ll of Figure 16.

Figure 18 is a top View of the insert member of the last three views. i

Figure 19 is a View similar to Figures 10 and l5, of a further modification of thefe'male insert showing a key fastening for the insert and a lstud member, both in position for engagement with the insert. y

Figure 20 is a view similar to Figure 19, showing the key fastening and stud engaged,this` figure being taken on the line 20--20 of Figure 21.'

Figure 21 is a top view of the work in Figure 20, with the stud in section on the line v2I---2I of Figure 20, this view being greatly enlarged.

Figure 22 is a top view of the female insert of the preceding figures, and I Figure 23 is a vertical longitudinal section of the insert on the line 23-23 of Figure 22.

Figure 24 is a vertical sectionalyiew of a support body structure vwith the female insert engaged therein, showing a modification of thekey fastening. n

Figure 25 is a top view of the structure of Figure 24.

Figure 26 is a vertical sectional view of a further modification of the female insert and its fastening, on the line 2li-28 of Figure 27, while Figure 27 is a horizontal sectional view on the line 21-21 of Figure 26.

Figure 28 is a longitudinalsectional view of a further modification of the insert and 'work'in which it is engaged, representing a simplification of the insert and its fastening.

There is illustrated in Figures 1 to 5, a form of the invention especially adapted tol be embedded as a stud in a body structure, by means of which other parts may be secured to the body structure, eitherremovably or permanently, 'as desired.

The illustrations in the several Views .are full size of embodiments of the invention as-,heretofore used, although it is adapted to be produced in larger and smaller sizes, as will be readily-appreciated. On the drawings, a portion lof aV body on the structure is shown, such as might be formed o f wood, or other yielding material, and this may include some of the modern plastics, and also soft metals, as will be readily appreciated, the body being designatedat V25. The body is shown. as drilled to a depth suitable for 'reception Qi a.

shoulder 30. In the case of wood, plastics and other materials of correspondingly yieldable nature, the bore 28 is formed as stated, with a diameter slightly less than that of the threaded part of the stud and is cut smooth, the stud being screwed into the material 25 in such manner as tocompress the surrounding material and cause the latter to fit into the threads of the stud. In harder materials the size of the bore 2B may be specially proportioned to the diameter of the threaded part of the stud engaged therein to permit a more or less flowing conformation of the material'25 to the threaded part of the stud without .excessive compression such as might tend to split-or fracture the material 25.

A locking member 33 is provided, which in the present instance is substantially vin the form of a hexagonal'nut: blank, split at one side so as to form a C-shape, with a slight gap 34, this C- shaped locking member being of substantial thickness in proper proportion to the density of the material 25, and ordinarily, for use in wood, its thickness is slightly less than half the length of the threaded inner portion of the stud. The locking member is slightly bevelled at its angular part, which constitutes the lower part'of the locking member, as illustrated at'35 and the circular inner side 36 of the locking member may be smoothly finished and substantially cylindrical with a diameter approximating that of the smooth portion 32 of the stud,or slightly less. The diameter of thelocking member 33` across opposite angles thereof is slightly greater than the diameter of the enlargement of the opening in the work 25 formed by the rabbet 29, so that when the lock is set around a stud 26 engaged in the bore 28, the angles ofthe lock set out over the material 25 slightly beyond the rabbet, substantially as indicated in Figure 2, more or less. The lock is also preferably of a size to snugly fit the smooth portion 32 of the stud, and it may be initially slightly smaller in size, so that it is sprung slightly in order to engage around the portion 32, requiring a slight driving fit, although' this is not entirely essential, and the lock may be slightly larger than the portion V32 and still function for the purposes in view, as will be disclosed.

In'the assembly of the parts, the bore 28 being drilled properly and rabbet 29 formed, the stud is introduced and screwed into the bore, without the lockingcollar 33 in final position, although it may be disposed upon the stud so as to lie above the material 25 while the stud is being screwed into place.V After the stud is screwed home, substantially as 4shown in Figure 1, a driving tool is engaged with the lock 33 and force applied suffrcien't to press or drive the lock collar longitudinally downward aroundthe stud and into the material 25, to the position or substantially the position shown in Figurel, although the lock lap device'may lie slightly below the circumjacent mousse;

outer surface of the material 2.5,. as will be understood: .'Thevstud being .so mountemparts, objects, or materials lto beV secured't'o the 'body struc-ture: 25T may then be. engaged upon thev body 25 around the, stud, substantially as shown at 31,: and. se;- cured'in placezby means of a nut or the like 38, screwed upon an outer threaded portion' of the studgthe threads of this part conforming to usual practices in machine screws and the like.' By thisl construction, shear stress transmitted from the attached part 315 to the stud will 'be' communicated by the studi to the lock collar 33f first, and by the latter transmitted to the material 25 overA an extremely enlarged area, soA that thel liability of the stud working loose in the material 25 will'be greatly minimized, as will 'be appreciated. Atthe same time, the stud- -is heldvandv locked' against rotation by the compression of the locking member 33- thereupon, and' eng-agement of the angles of the lock member in the material 25. The locking of the member 33 upon the stud 26- -is enhanced or increased, and may be alone caused by, the wedging of the lock member in the material as it is forced downwardly intothe'rabbet 28, the material 25 pressing in upon thesiezles of the lock memberA so asto compress it against the stud. This at the same time minimizes the liability of opening the locky member byf tendency of the stud 26 to lean or Work under shear stresses, as will be readily understood. The material o f'the'l stud may'correspond to the-'material customarily' used in stud'bolts and machine screws or `other screws, depending upon the nature 'of the materials used, and the stresses being' sustained' by the fastenings which comprises the Jwhole assembly as illustrated in Figure 1.

In Figures 6 to 8, inclusive, the construction which may conform to that previously described is employed, except that in addition, a key lug 4U is formed upon the stud close to the lower thread--l ed portion, so as to vlie within the yrabbet 29', the

stud 2.6 in this instance being either Yformed ,with a complete encircling collar thereon initially, or the lugsmay be formed by other familiarv methods for forming corresponding parts, of which there are a number ywelly known. form of vthe invention, the parts are assembled as rst described .and when the lock 33 is put Yin place, it is positioned with the gap 3 4aligned the lock is in place, By this means any tendency y materiarinwhich rastening is engaged' being indicated at 45, which would ordinarily be: onehalf an inch. thickiv The anchorage meinberlin this instance consists .of an interiorly threaded and: exterioritf 'threaded tubular member, sleevey or bushing 66', the external threads 41 uponwhicn are of greater depthvand pitch than the internal threads, and' across theouter-endz-of' the bushingr a slot 9 is formed, suitable iio'rr the reception of' a screwdriver' er1-the like, tor .engaging thev bushing' in the body material 4.55. At diametrcally opposite sides external .longitudinal key slotsl are formeel, these key slots being iiat bottomed in. the. present instance, although they 'f may :be otherwise shaped, las, wii'l ybe indicated hereinafter, and in this instance, they arepracticaliy'ofI the. same, or slightly morethan, the

depth of the'threads 41. Respective key pieces 51' are providedy adapted: to-be engaged slifdably being turned inwardly at right. angles, so as to set the strip slots 49 of the'anchor piece, as shown; in Figures 11 and l2'. -I The: outer ends ot the keys it may bev apertured as' at'52, to' facilitate extraction, 'should that become necessary. These endsxmay be bent in-.to thev slots l! after being driven into place.

the-use ofthe last described vform 'of the invention, the lbody material'v 45 is bored to a deptlrsumcient to enabler-the. anchorage" piece to be ser'ewed'thereinto toiits fuliI depth, as-show-n in: lgu-resl I0 11,y the bore being preferably of slightly smaller diameter than the external diameter of vthe anchor piece, so thatthe external SISA threads ofv the anchor will compress the material In .the use of this f of the vstud 26" to rotate is prevented by engagement of the lug against one side -or the other-lof vthe notched gap- 34. i

1 In cases where a very large stud is to be mounted, they key is made simply byfform-mg a radial bore-in the stud 26', which is otherwise substantially the same as the formshown at 2.6, and then a pin 4|, set therein by a conventional ,practice.- The outer endof the'pin is proportioned and shaped so as to rit in the gap of thelock de- .connection with the plywood; In instance, f

the article is illustrated considerably enlarged,

from its ordinary size, in Figures 10 to 14, a body surrounding the bore.- and become fitted thereinto, aswill'beunderstood.y f

This 'style of `anchorage may also be used in quarter-inch lrl'ywood,`A that is to saypplywood havingA a total thickness of one-quarterinch, and is useful where'braokets or otherzpieces or parts must 'besecured to 'such thin plywood'- in. situations where a nut cannotbe engaged with a bolt at the back of 'the plywood, and by the use of my invention'y the' need for such nuts in most instances 'is obviated. #Where the bracket or object to' besecured is one thatl'may bev sup-r I ported properly Say, a No. 8 screw, with threads 32j to the inch, it is ordinarily adequate to make the insert as last described one-quarter inch in external diameter, with 28 exterior threads to the inchv for use in quarterirl-chE plywood.y The diameter of the insert `may 'be greater, ofcourse, where Anecessity sov indicates, but it is not; desirable to 'hayefthe threads much, if any, coarser, than 28 tof the inch, where such thin plywood is involved.

, The insert mayffbe made of the vsame length for' use'in quarter-inch plywood as for in thi-cker'fmaterial's, substantially inthe proportion and described, in Figures lo `to 14,v in which event the insert would proect at .the back side of the thin: plywood', which' would not be objectionable in many situations. case of need, the measurement, of "the `anchorjpiece 46 longitudinally thereof Vmay bedecreased, asy will beunderstood.' .For engaging bolts, the diameter of the pieceand the size of the :internal threads are correspondingly increased,l asl will be undersmd' .Y K

' *After the anchorage r:piece 4f is screwed into 4the materiair 45 fully, the key members' 52| are driven' into place. as shown in Figure .11, and

/ 'thereafter-dimora stud for other screw fastening lmay `be engaged-in'. the anchorage. bushing in in these key slots, the outer ends of the key pieces" accordancewith conventional uses ofsuch fas-i tenings@ i 'f As shown in, Figures 15to 18,'this typeof bush-V ing anchorage may beA modified by the omission of the end'slot 49,v a vbushing 46 ,being` shownin these last mentioned views, which corresponds in size and dimensions and manner of use to the bushing 46' previously described. rI-his bushing is further'modied by the provision of key slots 53 at opposite sides extended longitudinally'there'- in and being of somewhat greater depth relatively than the slot Vl) in the previously described form ofthe invention, so that nails 54 maybe driven into the keyslots after the. bushing' has been' screwed into placexin the bodyrnaterial 45, the nail becoming embedded inthe material 45 at each side ofthe b'ore into -which'the bushing is screwed;

It will be apparent that the key devices 5l and 54 will prevent rotation of the anchorage bushing in the material 45-under ordinary usage.

In Figures --l9 to 23, a further modification of the bushing is shown in whichv proportions and manner of use are the same as describedin the last precedingl two fforms of the invention, `but instead of the channeled key-slot at the side, a fiat 55 is-*formed on the side 'of the bushing extending throughout its length. After itis screwed into place in the` material 45,1a broad semi-oval piece 56 is driven beside' the bushing into the material y45'; as indicated'in Figures 20 and,-2l. In Figures- 24 Iand 25 a further ymodiiication of -the anchorage of the bushing is shown, wherein the bushing 51 is formed without interruption ofthe thread exteriorly, though otherwiseconforming generally to'the sizes and proportions previously indicated. An opening or passage 58 is formed longitudinally inthe wall of the bushing, extending throughout its length and open on both ends,` so as to receive a pin 59 of complementary form and size therethrough, whichmay vbe inserted slidably in the longitudinal opening, and driven into the material 45 at theinner end of the bore. This has advantages in case the material 45 is quite hard, and might tend to bend the key pieces i if driven beside the bushing, and also enhances the security ofthe hold of the external threads of the bushing in the material-45. A

Iii-Figures -26 and 27 a forml of the invention corresponding to that shown in Figures to 18 inclusive, is illustrated, except that but one key slot is formed at the sides ofthe bushing 46-a which in most instances will be foundsuilicient,

a nail'54v being used as a key corresponding to the nail 54 'before mentioned, and this anchorage ture of the work. In the last mentioned two views there is also illustrated a bracket Apieceiil shown held by means of' a bolt 6I -and nut 62, and indicating how the securing ofa piece to the-body l over the bushing will-also serve to hold the key' at the side of the bushing against accidental removal or displacement. .-n A

The locking pins-5|, 56 and the like, may,if desired, be formed of metal or wood or a suitable adhesive may be forced into the key slots sofas to form the locking means. v

In Figure 28 there is illustrated the use of a con-V cealed locking means which is inserted in thebore t before the engagement of the anchorage bshing therein, the' structural material' in which'v the bushing is to be engaged being indicated at 63, the bore 64 formed therein for reception of'the anchorage member being formed of a slightly f' greater depth than required for the mere insertion ofthe anchoage member, but1being similarly of a small vdiameter so that the threads ofi the anchorage member will press intothe material 63. At *the inner end'of therbore there is inserted a washer of fibrous or other slightlycompressibleV friction material, the thickness of which is suilicientto permit it to becompressed in some degree by the anchorage insert v66 shown in the last mentioned figure, and in this case, the anchorage is of the'simplest possibleform, being formed without interruptions in the external threads, although itsinner end face -may be treated or Worked to enhance friction, if desired;

It should be noted that the washer 65 is formed with an opening slightlyl smaller than the threaded-borethrough the bushing 66 and preferablythe stud orother fastening to be engaged in thev anchorage sh-all'be threaded over a suiiicient part of its inserted end to pass through the bushing 66 and the washer y ,65,l thereby becoming locked by the latter against casual unscrewing, lthe lwasher' thus being further compacted and adding. to the security of the lock upon the bushing. vIn this way, the single member 65 performs the double function of locking the bushing and thevfastening screw engaged through the bushing.

While I have illustrated my invention and described it ina specific manner of use and proportion of parts and nature .ofmaterials, it will be understood that this is exemplary, and that incorporation of features of one modification in other forms of the device may be carried out without departing from the spirit of the invention, and likewise, .variations in the nature of the ma.- terials, proportions, construction and arrangement of parts may also be carried out without departing from thespirit of the invention except as more .specifically limited vby the appended claims. n

While I havereferred principally to wood and particularly to plywood or material such as plywood, as the, material in or on which my invention is lmost important at the moment, it will be understood that such references, particularly in the claims, shall include generally compressible materials, including metals, as aluminum, magnesium, lead, plastics, ber products and other I correspondingly compressible materials.

I claim: v

' 1 .`A` device of the character described comprising a tubular body internally and externally threaded, the external threads being traversed by longitudinally extending grooves, there being a diametrical slot at the top of the body the ends of which are arranged'over said grooves, and a key adapted to be `drivendown through one of said grooves and have its head positioned in said slot. l 2; 'A device of the Vcharacter described comprising 'ai tubular body internally and externally threaded, the externallthreads being traversed by longitudinally extending grooves, there being a diametrical slot at the topV of thefb'o'dy'the ends of which are arranged over said grooves, and a key adapted to be driven down through one of said grooves and have its head positioned vin said slot, said head being apertured.

3. A device of the class described comprising a tubular bodyinternally and externally threaded said body having a diametrical slot in its top and grooves extending downwardly across the external threads from the ends of said slot adapted to "i, receive keying devices.

. -WHITNEY E. VGREENE 

